Dr Despoina Denaxa-Kyza

It is estimated that nearly 4% of the paediatric population worldwide have a diagnosis of food allergy.

The diagnosis of food allergy is based on detailed history of the symptoms and is confirmed or denied with the aid of skin prick tests and specific IgEs where indicated. The interpretation of investigations can be tricky particularly in an atopic child where other causes of atopy can lead to false positive blood results. Same with skin prick tests there are limitations and doing tests blindly in order to ‘’fish’’ a cause of symptoms is not useful as there can also be false positive results due to sensitisation and not clinical allergy.

The gold standard for diagnosis of food allergy is double blind food challenge where both the patient and the clinician are not aware if the food provided contains the alleged food or is a placebo. However, this is mainly reserved for research purposes and in clinical practice we proceed with an open food challenge where indicated and safe to do so. During that process a child is advised either at home or in a supervised clinical environment to try the alleged food in increments and will observed for symptoms. This is a common process to introduce food previously avoided where there is suspected clinical history but investigations did not show sensitisation.

Previously the mainstay of management has been avoidance whereas  now we try to delabel as much as possible or at least introduce cooked form eg of milk or egg into the child’ diet with the hope they will maintain some tolerance. Tests will be periodically repeated to assess level of sensitisation and work further on introduction of the alleged food or continue with avoidance.

My role is to assess whether your child has true food allergy as there are other conditions like viral illnesses, contact dermatitis, eczema flares and in infants colics and reflux that mimic food allergy. Whether we proceed or not to do further tests depends on the type of suspected food allergy. There are mainly two typeds of food allergy: